Illinoian to Late Wisconsinan stratigraphy at Woodbridge, Ontario

Near Woodbridge, northwest of Toronto, Ontario, a 15 metre-high railroad cut and associated borrow pit, first excavated in 1962, exposed a multiple till sequence and intervening fossiliferous sediments. Work over the next 35 years revealed that Illinoian York Till, early Wisconsinan Sunnybrook Till,...

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Bibliographic Details
Published in:Canadian Journal of Earth Sciences
Main Authors: Karrow, P F, McAndrews, J H, Miller, B B, Morgan, A V, Seymour, K L, White, O L
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 2001
Subjects:
General Earth and Planetary Sciences
Scarborough
Tundra
Online Access:http://dx.doi.org/10.1139/e00-108
http://www.nrcresearchpress.com/doi/pdf/10.1139/e00-108
Description
Summary:Near Woodbridge, northwest of Toronto, Ontario, a 15 metre-high railroad cut and associated borrow pit, first excavated in 1962, exposed a multiple till sequence and intervening fossiliferous sediments. Work over the next 35 years revealed that Illinoian York Till, early Wisconsinan Sunnybrook Till, and late Wisconsinan Humber till, Halton Till, and Wildfield Till are interbedded with fossiliferous sediments equivalent to the Sangamonian Don Formation, early Wisconsinan Scarborough Formation (>50 ka BP), and middle Wisconsinan Thorncliffe Formation (45 ka BP). A complex periglacial record displays multistage fossil frost wedges, indicating intervals of severe climate in late Illinoian and early Wisconsinan time. Cored boreholes indicate deep gravel below and a till on Ordovician shale bedrock (Georgian Bay Formation). Vertebrates, molluscs, ostracodes, insects, and plants (diatoms, wood, seeds, pollen) indicate mostly cool conditions (boreal to tundra) for interstadial sediments. Interglacial conditions are represented by vertebrates, molluscs, and plants above York Till. Many taxa are new to the Quaternary of the Toronto area.

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